Clock^{Gt(P007F12)Wrst}

A "FlipROSAgeo" genetrap inserted in intron 2-3 of the Clock (circadian locomotor output cycles kaput) locus disrupts gene expression to create a null allele. Loss of expression (confirmed in hypothalamus, cerebellum, liver and kidney) does not severely attenuate the expression levels and oscillations of other core circadian transcripts.